Supercapacitors are strong future candidates for energy storage devices owing to their high power density, fast charge-discharge rate, and long cycle stability. Here, a flexible supercapacitor with a large specific capacitance of 443 F g-1 at a scan rate of 2 mV s-1 is demonstrated using nanotube-reinforced polypyrrole nanowires with hollowed cavities grown vertically on a nanotube/graphene based film. Using these electrodes, we obtain improved capacitance, rate capability, and cycle stability for over 3000 cycles. The assembled all-solid-state supercapacitor exhibits excellent mechanical flexibility, with the capacity to endure a 180° bending angle along with a maximum specific and volumetric energy density of 7 W h kg-1 (8.2 mW h cm-3) at a power density of 75 W kg-1 (0.087 W cm-3), and it showed an energy density of 4.13 W h kg-1 (4.82 mW h cm-3) even at a high power density of 3.8 kW kg-1 (4.4 W cm-3). Also, it demonstrates a high cycling stability of 94.3% after 10 000 charge/discharge cycles at a current density of 10 A g-1. Finally, a foldable all-solid-state supercapacitor is demonstrated, which confirms the applicability of the reported supercapacitor for use in energy storage devices for future portable, foldable, or wearable electronics.
Bibliographical noteFunding Information:
This project was supported by the National Research Foundation (NRF) funded by the Korea Ministry of Science and ICT (2018R1A2B2006640, 2016M3A7B4909581) and Global Frontier Project from the Center for Integrated Smart Sensors (CISS-2011-0031866).
© 2020 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Chemical Engineering(all)